Internal combustion engine



I Sept. 1, 1931.

F. A. BULLINGTON INTERNAL COMBUSTION ENGINE Original Filed Aug- 4. 1925 3 Sheets-Sheet 1 INVENTOR Sept. 1, 1931. F. A. BULL-INGTON INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet 2 Original Filed Aug. 24 5 1N VENTOR Sept. 1, 1931. FLA. BULLINGTON INTERNAL COMBUSTION ENGINE Original Filed Aug. 24 1925 3 Sheets-Sheet 3 11v VENTOR V s3 k 885 gxau \Skl wkann $53 .555

Patented Sept. 1, 1931 :JNITEDASTATES PATENT A. BULLiNGTOKyOE Ka sas orrY, meson-n1 mama]. commsrron ENGINE J Application filed August 2'4; 1925; Serial No. 52,070. Renewed November iii/ isen,

This invention relates to internal combustion engines in which opposed pistons arranged in pairs work in an.annular piston space or "cylinder, the pistonsof each pair 6 oscillating through afixed arcuate path in contra-distinction to those engines which include pistons rotating abouta common axis and which accelerate and decelerateaccording to the functions to be performed in their. 1 operativecycles.

For example, in the present invention each piston of each pair on one rotor is complementary to. both pistons of the other pairfon a separate rotor to provide working spaces, this being due to the fact that the complementary pistons have equal and opposite actions so that any twoopposed pistons move equal distances apart to take in a charge in the space between them; then move one toward the other to compress the charge, then move apart at the same relative speeds when the charge isburned to developthe power strokes of the. pistons, and finally move one toward the other to exhaust the burned gases to complete the cycle of operations, generically conforming to, the four cycle principle. All operations of each piston are confined to,

a fixed arc, each piston having a fixed amplitude of movement.

'In the illustrated embodiment-oi the invention I- have showntwo pairsof pistons,

' mounted upon two rotors, working in a cyl- I I the two pistons which move clockwise during the pistons movements beingcarried by one tor-clockwise being mounted upon the other rotor, so there is a'balanced relation between 40 the two rotors.

The-two rotors are provided with piston arms connected to a two-pin crank shaft by {connecting rods, the pins being 180 degrees apart so that. there are two revolutions of the crank 'shaft'for each operative cycle of the piston arrangement, and sincethe axes of the crank pins,connecting rod bearings, I and connections between the piston arms and the connecting rods at dead center positions :on the line 66 of Figs. 3 and5.

are all in a common planepassing through rotor andthe' two pistons which move coun-.

chamber at the end of the compression action,'the,co1nbustion' chamber serving as a compressed fuel charge receiving chamber.

As a result the working strokes of the pistons. are increased over what would be possible if the working chamber were large enough tocont'ain all the fuel prior to ignition. 'An arrangement for causing turbulence to occur within the compression chamber is associated with a communicating passage between the combustion chamber and the working chamber corresponding thereto.

All the. combustion chambers are sup lied with fuel from a common intake an all working chambers connect at proper intervals with a common exhaust.

There is means provided for introducing a non-combustible volumetric fluid into the working chambers to-provide a pre-compression of the fuel charge prior to the compression actions of the pistons.

There are other important featuresof this invention which distinguish it from other j inder or piston ehambercarried by, a stator, Ik j motors but these will be referred to hereinafter, reference being had to the accompanying drawings, in which and the section through the crank case being in a vertical plane.

Fig. 2 is a view of the stator with the front half removed.

Fig. 3 is a sectional view on the line 3-3 ofFig.1.

Fig. 1 is a developed sectional view on the line 44 of Fig l. r

. Fig. 5 is a sectional viewg'on the'line 55 of Fig. 1.,

Fig. 6 is a sectional view-through the stator Fig. 7 is a front, elevational view of the crank case, and

Fig. 8 is a fragmentary sectional view through a slightly modified form showing a separate spark plug for each combustion chamber.-

The stator is shown as comprising two parts 1 and 2, secured together to provide an annular piston space or; cylinder 3, hav ng a slot 4 at its inner circumference communl'c'atin with the rotor chamber-5;

%he parts 1 and 2 are provided with water jackets 6 and 7 to cool the stator in a -'well understood manner. The part 1 has a central bearing 8'to receive the end or hub 9of the hollow shaft 10, which carries the rotor 11 inthe rotor chamber 5.: The oppositeend of the shaft: is mounted in'a bearing member 12 in the crank case 13 and on "the shaft 10 is avpiston arm 14, connected to the pin 16 of the crank shaft by a connecting rod 17; it

. beingunderstood thatthe crank shaft-'is-a two-pin'crank shaft, one pin being designated 16 and the other 18. The pin 18'is connected to a piston arm 19 onthe hollow shaft '20 sleeved on shaft 10by'a' connecting rod21.

. The shaft 20 carries a rotor 22 in rotor chain her 5, the inner faces of the rotors 11' and 22 being inintimatecontact and the outer faces being incontact with packings Q3 and 24 in the rotor chamber 5. (See Fig 1.)

Suitable bearings may be provided between the shafts 10 and 20 as indicated at 25 and 26. The lrotors 11 and '22 carry pistons'27 and 28. vThere are four pistons, two on each rotor. Those on one rotor overlap the other' rotor and are secured to their respective ro- 1 ing 12.

On one end of the crank shaft is a fly wheel.

tors in a well understood manner. The movements of the pistons for their various operations will be clearly described hereinafter in connection with the method of admitting the fuel, compressing it, igniting it, and ex hausting it, it being understood that the engine works on the four cycle principle.

The stator is provided with a flanged con nection 29 bolted to the crank case by the bolts 29. The crank case has a slot 30in its end nearest to the stator so that by removing the cover 31, the screws 32 and 33 in the connecting rods, and the screws 34 in bearing cap 12, and removing the wrist pins 34 and 35,

the stator with itsentire piston and shaft assembly can be easily separated from the crank case. I I

The crank shaft 15 is shown as mounted in bearings 36 and 37 in the crank case and in the web member 38, which carries the boar- 39, while at the other endis a pinion meshing with a gem i1 on the stubshaft4'2 in;

hearings in the web member38 and the end of the crank caserespectively. The stub shaft may be the driven shaft or power take oif, or

power may be delivered direct from the crank is in a bearing46 at the end of a truncated conical valve 47 in a truncated conical valve seat 48in the partlofthe stator. Thebearing 46 is in the form of a journal'or hub and rotates with the valve 47 in a bearing 49 in the part 1 of the stator. The other end of the valve '48 rotates on the bearing56 car ried by'the removable collar 51 secured to the part 1 of'the statorby bolts 52. The valve has a slight .endwiseor longitudinal movement, being urged .to seating positionby an expansion spring 53, once-nd-of which bears againstthe-end flange 54 ,of the collanand the other against the bearing-50, When the valve expands, it will tend to stick in its seat but this tendency will bezovercome by the roller 55 on shaft 44,'whichwill tend to ride upon the inclined face 56 of the lug 56 to impart a slight longitudinal movement to the,

valve against-the action of the spring 53, and lnasniuch as the posltive cam action of the -rolleragainst the lug willebe greater than the yielding forcezofthe spring, the valve will 'always'be relieved from its tendency to stick \Vhen it is' free to rotate, the lateral thrust, of

'the'roller'55 against thelug-56 will be sufficient torotate the valve so-tlrat its ports may register with'the proper. combustion chambers, exhaust ports, etc.

' As heretofore pointed out,-there is a separate combustion chamber for each working space in the stator and inasmuch as there are two palrs of pistons, one pair on each rotor with the pistons of each-pair 180 degrees apart with the piston strokes equal toward. and away one from the other, there will be four working spaces corresponding to' four cylinders so the motor as shown will,

in effect, be a-four cycle, four cylinder motor.-

Since" there are four working spaces there will be four com-bustionchambers, one ,for each working space.- Theseare designated 57, 58, 59 and 60 (see Fig.3), They are 1 grouped aboutthe valveseat 48 within'which the valve '47 vrotates and they communicate with their working spaces through theexcent-rically located passageways 57, '58, 59

. and .60' (see Fig.3), .The hollow, truncated,

conicalrvalve receives the fuel from the in- .takeport 61" and delivers the fuel to the re lspective combustiou chambers tln'oughthe 'port 62. fThevalve has arecess 63 providing ,afpa'ssage to establish communicationbetweenthe port 64and the manifold '65. The

manifold 66 is adapted to communicate with Therefore, most of the burnt gases will exfi'haus't. th'roughthe manifold in the stator rather'th'anthrough the pocket in the valve. This is important because if "allthe products ,of combustion exhausted throughthe valve,

. burnt gases which pass through-the recess 63in't'o manifold open to atmosphere are .those (lispliace'df at practically "atmospheric pressure when the opposing pistons are moving one toward the other during theirscavenging strokes. The'pressures at which the burntgases are exhausted through the outlet 67 for the manifold 66 will be determined by the position'of the valve 67' in the outlet port 7."(SeeT ig.5.)

Ifsome of the burntgasesare trapped in the manifold 66 by partly closing the valve 67, some of such gases will be taken into the working space betweenopposing pistons 27 and 28' when the pistons reach the limit of their intake strokes; the amount of noncombustible secondary volumetric fluid supplied to the working space is determined by volumetric fluid.

the amount of vacuum in the working space between the pistons at the timethe pistons reach the limit of their intake strokes and the pressure of the .exhaust gas in the manifold 66,-atwhich time they will open'the ports 66 to the working space between them, as shown in Fig. 4. In this figure the working spaces are all designated 28, therebeing four shown because the figure isadeveloped view of the cylinderin the; stator and-the pistons. It will, therefore, be seen that the non-combustible secondary volumetric fluid is charged into the working spaces in strata with the combustible fluid between the charges of \Vhen' a rotary valve such as is shown in Fig.1 is employed in an' engine constructed in accordance with-my invention, it is ossible to utilize a single spark plug foif all the combustion chambers. The plug 68 is screwed into the seat 69 in the,end\ of the recess 70 in the valve 47 with its pdints or electrodes in the pocket 71, adapted; successively register with the respective combus-' tion chambers 57 to 60, both inclusive. When the pistons are in positions to move on their expansion or power strokes to insure the combustion of the fuel takingplace in each combustion chamber at the proper period during the operative cycle of the en- "gine', current issupplied to the spark plug from "an approved ignition system (not shown) to a contact 7 2, against which-one end-of the spark plug abuts, as shown in shown in Fig. 3 the valve 47 is in position to supply fuel to the combustion chamthe high temperatures of the gases would tend to warp the valve. 1 However, :theonly v ber .60W1'll be charged with fuel ready to ber 57 throughport 62 upon a slight clockwise movement of the valve, the pistons having just finished their exhaust strokes and are about to move away one from the other to take inthe charge supplied to the combustion chamber. 57. fuel is being supplied to combustion chamber 57, chamber 58 will beexhausting, the fuel in chamber 59, having pistons 'associated therewith and the'chambe compressed and ignited when the spark plug pocket 71 registers'with the chamber. 60, it .being understood that a suitable timer will be provided in the ignition system to cause a spark to jump the gap across the electrodes of the spark'plug at proper intervals.

As heretofore explained, all pistons have the same amplitude of movement for any given speed 0 the engine and they move back and forth or oscillate in constantly recurring arcs, instead of advancing in a circular path about a common axis. With such a construction I am enabled to build an engine having certain advantages over other known motors.

For example, practically perfect balanced performance isassured and a rotary valve been ignited, will 'be expanding between the may be employed for admitting the charges to the combustion chambers and exhausting some of the products of combustion, the larger volume ofthe products of combustion at the initial exhaust temperature being passed out throughthe ports 66 into the manifold 66. The cooler gases during the scavenging strokes of the pistons are exhausted through the pocket 63 to the manifold 65 to atmosphere. Therefore, I term the manifold 66 the primary manifold or exhaust because the initial exhaust passes through it while the manifold 65 receives only the products of combustion displaced by. the scavenging strokes of the pistons 27 and 28 at approximately atmospheric pressure, so it will-be seen that the valve will not be subjected to the maximum temperatures resulting from the products of combustion. Consequently the tendencyof the valve to warp will be reduced to a minimum.

The combustion chambers are preferably provided with removable cover members or plugs 73 so that the walls of the combustion chambers may be machined to provide smooth surfaces to reduce carbon deposits and promote maximum efficiency, as well as to permit removal of carbon and observation of'the spark plug terminals when expedient. The passageway establishing communication between a wor ing chamber and its respective combustion chamber is located excentricallv in relation to the combustion chamber, so that a fuel charge being compressed in a working chamber will pass to the combustion chamber in'a manner to cause turbulence in the compressed chargetherein.

invention'does not depend entirely upona rotary valve for successful operation but a rotary valve is recommended and while I prefer to employ a single spark plug for all the combustion chambers, it is possible to utilize a' separate spark plug for each combus'tion chamber; One such plug is shown in Fig. 8 It is'designated 7 4 and it is shown as screwed into-the end of thecombustion chamber 175 which communicates with the working spa'cefor which it is designed by a passageway" 7 6' corresponding to the. passagewags 57f fo'60 in Fig. 3 ther' modificationsmay be resorted to without changing the essential. principle of my invention I-reserve theright to make changes without departing fromthe spirit of the invention. I I

What I claim 'and desire to secure by Lettors-Patent is "11 In a four cycle internal combustion engine-,-*a stator having an annular passage "therein, pairs of pistons mounted-for oscillation in said passage and defining. working f chambers therebetween, and positivelyop- 'erated means controlling the admittance of fuel to-and the-exhaust of the products of -combustion from said working chambers whereby-each thereof has a four stroke cycle of operation.

v 2. In a four-cycle internal-combustion engme,1a stator having an annular passage therein, pairs of diametrically oppositev PIS- tonsmounted for oscillation in said passage and defining working chambers therebetween,

means controlling the movement of said pistons causing adjacent pistons .to oscillate simultaneously-- in vopposite directions and positively operated means controlling the admittanceof fuel to and the'exhaust of the -"products'of combustion from said Working chambers whereby each thereof has a vfour stroke cycle of operation.

f '3. In a four cycle internal combustion engine, a stator having an annular passage therein,'pairs of pistons mounted for oscilla iilOIl'll'l saldpassage and defining a working chamber between each pair of adjacent pistons and means controlling the admittanceof fuel to and the exhaust of the products of combustion from said; working-chambers of-operation. H

"4; In a four cycle internal-combustion en "whereby each thereof has a four stroke cycle;

(fine, a stator having an annular passage therein, pistons mounted for oscillation in said passage and definingworking chambers therebetween, each working chamber having a combined inlet and exhaust port, and means controlling the admittance of fuel to and the exhaust of the products of combustion from said working chambers whereby each thereof has'a four stroke cycle of operation,

5. In a four cycle internal combustion en-. gine, a stator having an annular passage .with j therein, pistons mounted for oscillation said passageand def ning working chambers therebetween, each working chamber having a combined inlet. and exhaust port, and means controlling the admittance of fuel to andthe exhaust of the products of combustion from said working "chambers whereby each thereof has a four'stroke cyole'of operation, said means comprisinga power drive'n valve associated with said ports.

6. An internal combustion motor comprising a casing having an annular cylinder, os-

cillating pistons in the cylinder, all having the same amplitude of movement, means controlling the amplitude of movement of'the pistons, a separate combustionchamber outside the annular cylinder for each space between opposing piston faces, means for establishing communication between said chambers and spaces, and a fluid distributing valve communicating with the intake for progressively admitting fluid into the respective combustion chambers.

7. An internal combustion motor' co'mprising a casing having an annular cylinder, os-. cillating pistons in the cylinder, all having the same amplitude'of movement, means controlling the amplitude of movement of the pistons, a separate combustion chamber outa side the annular cylinder for each space between opposing piston faces, means for estab-' lishing communication between said'chambers and spaces,and a fluid distributing coni ing the same amplitude of movement, means i controlling the amplitude of movement' of the pistons, a separate combustion chamber outside the annular cylinder for each space between opposing piston faces, means for establishing communication between chambers and span'-'es', "a fluiddistributing valve communicating with the intake for progressively admitting fluid into therespect-ive combustion chambers, and asingle sparkplug carriedby the valve, an"ignition pocket sue 'cessively registering'with thejrespective combustion chambers; said spark plug'having terminals in said pocket, a stationary terminal locatedsubstantiallyaxially of saidengine and'mea'ns on said plug engaging there- 9. A four cycle internal combustion'motor comprising va casing, p'airs of oscillating pistonsin'the casing, the casing having exhaust ports adapted to be uncovered in pairs at the ends of the working strokes of the p'istons,and positively operated means for admitting fuel into the spaces between the pistons.

10. A four cycle internal combustion motor said" comprising a casing, pairs of oscillating pistons 1n the casing, the casing having primary exhaust ports adapted to be uncovered at the ends of the Working strokes of the pistons,

5 means for exhausting burnt. gases at low pressure during the scavenging strokes of the pistons, said means being distinct from said ports, and means for admitting fuel into the spaces between the pistons.

11. A four cycle internal combustion engine:

comprising a casing having an annular chamher, an annular manifold about the chamber ,adapted to communicate therewith through adapted to communicate therewith through spaced passageways, oscillating pistons inthe chamber having simultaneous, oscillating movements in fixed arcs, the pistons having movements toward and away one from the other, the pistons uncovering the passageways when they move apart,"-means for supplyingfuel to the spaces between the pistons, a power delivery element connected to the pistons, a

. manifold ,having an outlet opening to atmosphere, and avalve in the outlet.

13. A fourcycle internal combustion engine comprising a casing having an annular piston. chamber, oscillating pistons in the chamber having fixed amplitudes of movements, a manifold having ports communicating with the spaces between opposing faces of the'piston s when the faces of opposing pistons are the greatest distances apart. to exhaust burnt gases at the ends of the expansion strokes of the pistons into said manifold, and to admit some of the burnt gases from the manifold to the spaces between the pistons at the beginning of the compression strokes of the pistons, means for admitting fuel to the spaces between the pistons, a power delivery element, and connections between the pistons and the power delivery element.

14. A four cycle internal combustion engine comprising a casing having an annular piston chamber, oscillating pistons in the chamber having fixed amplitudes of movements, a manifold having ports communieating with the spaces between opposing faces of the pistons when the faces of opposing pistons are the greatest distances apart toexhaust burnt gases at the ends of the expanmon to .all the spaces between the pistons.

sion strokes of the pitsons into said manifold, and to admit some of the burnt gases from the manifold to the spaces between the pistons at the beginning of the compression strokes of the pistons, means for admitting fuel to the spaces between the pistons, said means comprising a rotary valve common to all the spaces between the pistons, a valve-operating means, a power delivery means operated by the pistons, and means for operating the valve from the ower delivery means.

15. A our cycle internal combustion engine comprising a casing'having an annular piston chamber, oscillating pistons in the chamber having fixed amplitudes of movements, an exhaust manifold having ports communicating with the spaces between opposing faces of the pistons when the faces of opposing pistons are the greatest distances apart to exhaust burnt gases at the endsof the expansion strokes of the' istons and to admit some of the burnt gases rom the inani-f fold to the spaces between the pistons at the beginning of the compression strokes of the pistons, valve means for admitting fuel to:

the spaces between the pistons, a power delivery element, connections between the pietons and the power delivery element, and a spark plugcarried by thevalve means com- 16. An internal combustion engine comprising a casing having an annular piston chamber, oscillating pistons in the chamber, all having-the same amplitude of movement to provide working spaces between them, a

separate-combustion; chamber for each working space, the combustion chambers being grouped about a pommon center, a rotary inlet valve having a port cutting to successively register with the combustion chambers, 21

spark plug carried by the valve to successively ignite the charges in the combustion cham-' bers, the valve having an exhaust port to reg ister with the combustion chambers, a power delivery means, and connections between the power delivery means andthe pistons.

17. An internal combustion engine comprising a casing having an annular piston chamber, oscillating pistons in the chamber,

all having the same amplitude of movement to provide working spaces between them, a separate combustion chamber for each working space. the combustion chambers being grouped about a common center, a rotary inlet valve having a port cutting to successively re ister with the combustion chambers, the casing having exhaust ports to register with the spaces between the pistons when the pistons are at the limits of the expansion stroke,

a spark plug carried by the valve to succes sively ignite the charges in the combustion tween the power delivery means and the pistons.

18. An internal combustion engine com- I v prising a casing having an annular piston chamber having inlets and outlets, oscillating pistons in the chamber having working spaces etween them, a conical rotary inlet valve common to all the working spaces, a spring normally urging the valve upon its seat, a valve operating means loosely connected to prising a casing having an annular piston chamber, oscillating pistons in the chamber providing working spaces between them, there being exhaust ports at the ends of the working spaces to be covered and uncovered by the pistons, combustion chambers for the working spaces, a valvefor admitting fuel into the combustion chambers, a spark plug carried by the valve to ignite the fuel, and

' a. power delivery means connected to the pistons.

' 20. In an internal combustion engine, a piston casing, a crank case and a piston carrymg shaft extending from sald casing into said iliary inlet means for admitting inert fluid to said chamber adjacent the opposite ends thereof after the fuel mixture has been drawn into the same.

24. In an internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passage and defining working chambers there between, each working chamber having a combined inlet and exhaust port near the middle thereof and auxiliary inlet means for admitting inert fluid tosaid chamber adjacent the opposite ends thereof after the fuel mixture has been drawn into the same.

25. In a four cycle internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in .said passage and defining working chambers therebetween, said pistons separating from and a proaching each other in pairs to define chambers of simultaneously increasing and decreasing capacity, and means for establishing communication between the chambers of increasing capacity near the ends of the separating strokes of the pistons defining the same.

26. In a four cycle internal combustion engine, a casing having an annular passage 30 in to receive said shaft, and means detach- ;crank case. the crank case having a slot theretherein, pistons mounted for oscillation in said passage and defining working chambers therebetween, said pistons separating from ably connecting-the crank case and the piston casing with said slot adjacent said piston casing, whereby said shaft and the parts carried thereby may be assembled with said 5 crank case and removed therefrom by passing said shaft through said slot.

21. In a four cycle internal combustion engine, a "stator having an annular passage i therein, pistons mounted for oscillation in 0 said, passage and defining working chamberstherebetween, said passage being provided with a series of combined inlet and exhaust ports, each associated with one of said working chambers and open thereto at all 45 times, and combined inlet and exhaust valve means controlling the admittance of fuel to and the discharge of the products of combustion from said working chambers whereby each thereof has'a four stroke cycle of 0 operation.

.22. In an internal combustion engine, a caslng having an annular passage therein, pistons mounted for oscillation in said passage and defining working chambers there-- 55 between, each working chamber having a combined inlet and exhaust ort and auxiliary inlet means for admitting inert fluid in strata to said chamber after the fuel mixture has been drawn into the same.

23. In an internal combustion engine, a casing'having an annular passage therein,

pistons mounted for oscillation in said pas-"' sage and defining working chambers'therebetween, each working chamber having a combined inlet tindexhaust port and auxand approaching each other in pairs to define chambers of simultaneously increasing and decreasing capacity, and means for establishing communication between both ends of each of the chambers of increasing capacity near the ends of the separating strokes of the pistons defining the same.

27. In a four cycle internal combustion engine, a casing havingan annular passage therein, pistons mounted for oscillation in said passage and defining working chambers therebetween, said pistons separating from and approaching each other in pairs to define chambers 9f simultaneousl increasing and decreasing-capacity, one 0 said chambers being a suction chamber while another is an expansion chamber, and means for transferring secondary volumetric fluid under pressure from said expansion chamber to said suction chamber to give the fuel therein an initial compression.

v 28. In' an internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passage and defining working chambers therebetween, each working chamber having a combined inlet and exhaust port, and auxiliary inlet means for admitting inert fluid in strata to said chamber after the fuel mixture has been drawn into the same, comprising ports opening into said passage, 8. pair thereof corresponding to each working chamsaid pistons at the ends of their suction strokes.

29. In an internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passage and defining working chambers therebetween, each Working chamber having a combined inlet and exhaust port, and mixiliary inlet means for admitting inert fluid under pressure to said chamber after the fuel mixture has been drawn into the same, comprising ports opening into said passage, a pair thereof corresponding to each working chamber and being adapted to be uncovered by said pistons at the ends of their suction strokes, said combined inlet and exhaust ports alternating with said auxiliary inlet ports.

30. In a four cycle internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passage and defining workin chambers therebetween, each working cham er having a combined inlet and exhaust port and primary exhaust means, and means controlling the admittance of fuel to and the exhaust of the products of combustion from said working chambers whereby each thereof has a fou stroke cycle of operation.

31. In an internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said pas sage and defining working chambers therebetween, each working chamber having a combined inlet and exhaust port and primary exhaust means comprising pairs of ports associated with each working chamber and uncovered bysaid pistons near the ends of the expansion strokes thereof, and means controlling the admittance of fuel to and the exhaust of the products of combustion from said working chambers, said combined inlet and exhaust ports being located substantially midway between said pairs of ports.

32. In an internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passageand defining working chambers therebetween and combined inlet and exhaust means for each working chamber, comprising a separate combustion chamber, a port leading from said combustion chamber into the corresponding working chamber, and inlet and exhaust valve means associated with said combustion chamber. v

33, Inan -1nter'nal combustion engine, a

- casing having an annular passage therein,

pistons mounted for oscillation in said passage and defining working chambers therebetween, inlet and exhaust means for each working chamber, a combustion chamber associated with each working chamber, spaced therefrom and havinga capacity sufiicient to contain the major portion of the fuel charge passing into the same from the corresponding working chamber under compression action of the pistons, a port loading from said combustion chamber into the corresponding working chamber and ignition means associated with said combustion chamber.

34..In an internal combustion engine, a casing having an annular assage therein, pistons mounted for oscillation in said passage and defining working chambers therebetween, a combustion chamber associated with each working chamber and a port leading from said combustion chamber into the corresponding working chamber, said port opening into said combustion chamber so as to set up a condition of turbulence therein.

.35. In in internal combustion engine, a casing having an annular passage therein, pistons mounted for oscillation in said passage and defining working chambers therebetween, a combustion chamber associated with each working chamber, and a portleading from said combustion chamber into the corresponding working chamber, said port opening into said combustion chamber eccentrically thereof.

36. In an internal combustion engine, a

stator having an annular passage therein and an annular slot connecting therewith, pistons mounted for oscillation in said passage in ops "posite directions, pairs of disks extending through said slot and carrying said op sitely moving pistons to be oscillated there y, a crank case and driving shaft members on said disks extending into said crank case.

37. In .an internal combustion engine, a.-

cylinder member having an annular passage therein and an annular slot connecting therewith, pistons mounted for oscillation in said. passage inopposite directions, pairs of disks extending through said slot and carrying said oppositely moving pistons to be osci lated thereby, a crank case and telescoping driving shaft members on said disks extending into said crank case, one of said shaft members being ,journalled at one end in the cylinder member and at the other end in a bearing in the crank case.

38. In an internal combustion engine, a

cylinder member having an annular passage therein and an annular slot connecting therewith, pistons mounted for oscillation in said passage in opposite directions, a piston carrying disk extending'through said slot, a hollow shaft extending from said disk and a valve operating member extending through said hollow shaft.

39. In an oscillating piston engine, a cylinder member having an annular assage therein and a slot connecting therewith, pistons mounted for oscillation in said passe e in opposite directions, pairs of disks exten ing through saidslot and carrying said oppositelymoving pistons to be oscillated thereby, a crank case, telescoping driving members on said disks extending into said crank case, one

- L a bearing in the crank case,

of said shafts being jou'rnalled at one end in the cylinder member and at the other end in the other of said shafts being journalled on said first named shaft, operating arms on said shafts, wrist pins in the arms at their outer ends, a crank shaft having two crank pins spaced diametrically apart, each crank pin in alignment, with one of said wrist pins, and connecting rods connecting each crank pin with its aligning wrist pin and ada ted to have substantially simultaneous dea center sitions both on the same side of the crank s aft substantially in alignment with each other.

In testimonfi whereof I aflix my signature.

' F ANK A. BULLINGTON. 

